1. Field of the Invention
The present invention broadly relates to high accuracy timing sources and, more particularly, is concerned with a laser clock for providing a stable, highly accurate source of timing that will not degrade under acceleration and have low unit cost.
2. Description of the Prior Art
A current Air Force problem is to provide high accuracy timing for fighter aircraft. The clock must operate between -50.degree. C. and +95.degree. C. The clock must also operate under a 6 g load during an aircraft maneuver and up to a 10 g maximum load for vibration.
Currently, the clock is heated to above +75.degree. C. so that it can use the environment as a heat sink. To achieve this temperature, the clock must first be warmed up and then allowed to stabilize. However, the process of thermal stabilization needs to be reduced or eliminated because, in emergency situations, aircraft cannot set on the runway while waiting for the clock to stabilize. Another consideration is the cost of the clock. The cost of an aircraft grade Cesium atomic clock, currently used, is about $40,000.
Consequently, a need exists for an improved timing source adapted for use in modern Air Force fighter aircraft which does not degrade under high accelerations, requires little or no time for stabilization, and has a lower unit cost.